[ARM] 4137/1: Add kexec support

Add kexec support to ARM.

Improvements like commandline handling could be made but this patch gives
basic functional support. It uses the next available syscall number, 347.

Once the syscall number is known, userspace support will be
finalised/submitted to kexec-tools, various patches already exist.

Originally based on a patch by Maxim Syrchin but updated and forward
ported by various people.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 32 insertions, 0 deletions

diff --git a/include/asm-arm/kexec.h b/include/asm-arm/kexec.h
new file mode 100644
index 000000000000..8c1c6162a80c
--- /dev/null
+++ b/include/asm-arm/kexec.h
@@ -0,0 +1,30 @@
+#ifndef _ARM_KEXEC_H
+#define _ARM_KEXEC_H
+
+#ifdef CONFIG_KEXEC
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
+/* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
+
+#define KEXEC_CONTROL_CODE_SIZE 4096
+
+#define KEXEC_ARCH KEXEC_ARCH_ARM
+
+#ifndef __ASSEMBLY__
+
+#define MAX_NOTE_BYTES 1024
+
+struct kimage;
+/* Provide a dummy definition to avoid build failures. */
+static inline void crash_setup_regs(struct pt_regs *newregs,
+                                        struct pt_regs *oldregs) { }
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* CONFIG_KEXEC */
+
+#endif /* _ARM_KEXEC_H */
diff --git a/include/asm-arm/unistd.h b/include/asm-arm/unistd.h
index 97e7060000cf..0991b7bc3f78 100644
--- a/include/asm-arm/unistd.h
+++ b/include/asm-arm/unistd.h
@@ -372,6 +372,7 @@
 #define __NR_move_pages                 (__NR_SYSCALL_BASE+344)
 #define __NR_getcpu                     (__NR_SYSCALL_BASE+345)
                                         /* 346 for epoll_pwait */
+#define __NR_sys_kexec_load             (__NR_SYSCALL_BASE+347)
 
 /*
  * The following SWIs are ARM private.
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index d02425cdd801..696e5ec63f77 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -125,6 +125,7 @@ extern struct kimage *kexec_crash_image;
 #define KEXEC_ARCH_PPC     (20 << 16)
 #define KEXEC_ARCH_PPC64   (21 << 16)
 #define KEXEC_ARCH_IA_64   (50 << 16)
+#define KEXEC_ARCH_ARM     (40 << 16)
 #define KEXEC_ARCH_S390    (22 << 16)
 #define KEXEC_ARCH_SH      (42 << 16)
 #define KEXEC_ARCH_MIPS_LE (10 << 16)